目录结构

  1. $ tree identidock/
  2. identidock/
  3. ├── app
  4. │   └── identidock.py
  5. ├── cmd.sh
  6. ├── docker-compose.yml
  7. ├── Dockerfile
  8. └── Dockerfile.bak

identidock.py

  1. from flask import Flask
  2. app = Flask(__name__)
  5. @app.route('/')
  6. def hello_world():
  7.     return 'Hello Docker!\n'
  9. if __name__ == '__main__':
  10.     app.run(debug=True, host='0.0.0.0')

构建

  1. $ docker build -t identidock .

Digest: sha256:7a7e47efdfd6503afcf56a57f981bcc23d54211ad3b3c21cbe4bd597873fa6e1Status: Downloaded newer image for python:3.4
—-> 8c62b065252f
Step 2/5 : RUN pip install Flask==0.10.1
—-> Running in fa9fb047fee1
Collecting Flask==0.10.1
Removing intermediate container fa9fb047fee1
—-> 37fc7a1155ec
Step 3/5 : WORKDIR /app
—-> Running in 819ed30c1c35
Removing intermediate container 819ed30c1c35
—-> fe27c7494c03
Step 4/5 : COPY app /app
—-> 1855871f890a
Step 5/5 : CMD [“python”,”identidock.py”]
—-> Running in 7577e033d7bd
Removing intermediate container 7577e033d7bd
—-> 52a82f0b0f2a
Successfully built 52a82f0b0f2a
Successfully tagged identidock:latest

  1. $ docker images
  2. REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
  3. identidock          latest              52a82f0b0f2a        56 seconds ago      935MB
  4. python              3.4                 8c62b065252f        2 years ago         924MB

运行

  1. $ docker run -d -p 5000:5000 identidock
  3. 74103e65731ce6ee4713430964e618a2dca8cdc77fb7e03d08c8933706a6cca7

测试

  1. $ curl localhost:5000
  2. Hello Docker!

绑定挂载

  1. $ docker ps
  2. CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                    NAMES
  3. 74103e65731c        identidock          "python identidock.py"   27 minutes ago      Up 27 minutes       0.0.0.0:5000->5000/tcp   unruffled_perlman
  1. $ docker stop $(docker ps -lq)
  2. 74103e65731c
  3. $ docker rm `docker ps -lq`
  4. 74103e65731c

停止并删除上次运行的容器

docker run -d -p 5000:5000 -v "$PWD"/app:/app identidock

uWSGI:可立刻用于生产环境的应用服务器

这里出现报错，详情请见👇
容器pip安装第三方库报错PY
Dockerfile

  1. FROM python:3.4
  3. RUN pip install Flask==0.10.1 uWSGI
  4. WORKDIR /app
  5. COPY app /app
  7. CMD ["uwsgi","--http","0.0.0.0:9090","--wsgi-file","/app/identidock.py", \
  8.     "--callable","app","--stats","0.0.0.0:9191"]

CMD中启动一个监听9090端口的HTTP服务器，在9191端口启动一个数据统计服务器，其实我们还可以在运行docker run的时候，重新定义CMD内容

image.png

  1. $ docker images
  2. REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
  3. identidock          latest              9ee42844f0a2        2 minutes ago       938MB
  4. python              3.7                 9337bc3e7477        2 weeks ago         877MB
  5. python              3.4                 8c62b065252f        2 years ago         924MB
  6. $ docker run -d -p 9090:9090 -p 9191:9191 identidock
  7. a4a5d38590c458ce2520983eb1c4fffcd34afee20e9bdb6e8deb8a63845724bb
  8. $ curl localhost:9090
  9. Hello Docker!

细分权限,端口,用户提升安全性

  1. FROM python:3.4
  3. RUN groupadd -r uwsgi && useradd -r -g uwsgi uwsgi #创建uwsgi用户和用户组
  4. RUN pip install Flask==0.10.1 uWSGI
  5. WORKDIR /app
  6. COPY app /app
  8. EXPOSE 9090 9191 #声明主机和其他容器可以访问的端口
  9. USER uwsgi #以uwsgi用户执行这一行后面的所有的命令（包括CMD和ENTRYPOINT）

$ docker build -t identidock:1 .
$ docker run -d -P --name port-test identidock:1
0eafeb8f7195faf1919f680c830f64a9a035e025a50d5e3f3c715e301df3f327
-P 参数 随机选择一些高端口映射到容器的每一个已经EXPOSE声明的端口
dropann@dropann:~/using_docker_in_dev/identidock$ docker port port-test
9090/tcp -> 0.0.0.0:32769
9191/tcp -> 0.0.0.0:32768
通过环境变量和一个简单的脚本，按实际的运行环境切换不同功能
cmd.sh

  1. #!/bin/bash
  2. set -e
  4. if [ "$ENV" = 'DEV' ]; then #如果ENV变量设定为DEV，运行调试的web服务器
  5.   echo "Running Development Server"
  6.   exec python "identidock.py"
  7. else
  8.   echo "Running Production Server" #否则运行生产服务器
  9.   exec uwsgi --http 0.0.0.0:9090 --wsgi-file /app/identidock.py \
  10.              --callable app --stats 0.0.0.0:9191
  11. fi

其中exec命令的目的是为了避免创建一个新进程，以确保uwsgi进程能够收到所有信号，而不是被父进程拦截

  1. FROM python:3.4
  3. RUN groupadd -r uwsgi && useradd -r -g uwsgi uwsgi
  4. RUN pip install Flask==0.10.1 uWSGI
  5. WORKDIR /app
  6. COPY app /app
  7. COPY cmd.sh /
  9. EXPOSE 9090 9191
  10. USER uwsgi
  12. CMD ["/cmd.sh"]
  1. chmod -x cmd.sh
  2. docker build -t identidock .
  3. docker run -e "ENV=DEV" -p 5000:5000 identidock

一个简单的web应用

目录结构

  1. $ tree creating-a-simple-web-app/
  2. creating-a-simple-web-app/
  3. ├── identidock
  4. │   ├── app
  5. │   │   └── identidock.py
  6. │   ├── cmd.sh
  7. │   ├── docker-compose.yml
  8. │   ├── Dockerfile
  9. │   └── Dockerfile.bak
  10. ├── LICENSE
  11. └── README.md

Dockerfile

  1. FROM python:3.4
  3. RUN groupadd -r uwsgi && useradd -r -g uwsgi uwsgi
  4. RUN pip install Flask==0.10.1 uWSGI requests==2.5.1 redis==2.10.3
  5. WORKDIR /app
  6. COPY app /app
  7. COPY cmd.sh /
  9. EXPOSE 9090 9191
  10. USER uwsgi
  12. CMD ["/cmd.sh"]

docker-compose.yml

  1. identidock:
  2.     build: .
  3.   ports:
  4.    - "5000:5000"
  5.   environment:
  6.     ENV: DEV 
  7.   volumes:
  8.     - ./app:/app
  9.   links:
  10.     - dnmonster
  11.     - redis
  13. dnmonster:
  14.   image: amouat/dnmonster:1.0
  16. redis:
  17.   image: redis:3.0

identicon.py

  1. from flask import Flask, Response, request
  2. import requests
  3. import hashlib        #导入对用户输入进行散列处理的程序库
  4. import redis
  6. app = Flask(__name__)
  7. cache = redis.StrictRedis(host='redis', port=6379, db=0) #建立redis缓存
  8. salt = "UNIQUE_SALT"    #定义散列函数salt值
  9. default_name = 'Joe Bloggs'
  12. @app.route('/', methods=['GET', 'POST']) #Flask默认只相应get请求,必须给route声明加入methods参数,宣告route能处理post请求
  13. def mainpage():
  15.     name = default_name
  16.     if request.method == 'POST':
  17.         name = request.form['name']
  19.     salted_name = salt + name
  20.     name_hash = hashlib.sha256(salted_name.encode()).hexdigest() #执行SHA256算法,以获取散列值
  21.     header = '<html><head><title>Identidock</title></head><body>'
  22.     body = '''<form method="POST">
  23.               Hello <input type="text" name="name" value="{0}">
  24.               <input type="submit" value="submit">
  25.               </form>
  26.               <p>You look like a:
  27.               <img src="/monster/{1}"/>
  28.               '''.format(name, name_hash)
  29.     footer = '</body></html>'
  31.     return header + body + footer
  34. @app.route('/monster/<name>')
  35. def get_identicon(name):
  37.     image = cache.get(name)        #检查名字是否在缓存中
  38.     if image is None:            #如果返回None,继续调用idention
  39.         print ("Cache miss", flush=True) #输出调试信息,表示没有在缓存中找到图像
  40.         r = requests.get('http://dnmonster:8080/monster/' + name + '?size=80')
  41.         image = r.content
  42.         cache.set(name, image)# 把图像加入缓存,与名字关联
  44.     return Response(image, mimetype='image/png')
  46. if __name__ == '__main__':
  47.     app.run(debug=True, host='0.0.0.0')